Prepare and draw a titration curve for an unknown amino acid (which will be either histidine, glutamic
Question:
Prepare and draw a titration curve for an unknown amino acid (which will be either histidine, glutamic acid, or cysteine). Using this titration curve, you will determine each of the pKa's for the given amino acid and use that information to identify which amino acid you have been given to titrate.
1. Into a clean 250 ml beaker, collect 100 ml of one of the unknown amino acid solutions. Place on a magnetic stirrer with a magnetic flea. If the stirring block is also a heater, ensure that the heat is turned OFF.
2. Carefully position a pH electrode in the solution so that the bulb at the tip is completely immersed in the solution but, not close to the spinning flea as this may damage the bulb.
3. Record the pH of the original solution before you begin the titration.
4. Using a micropipette, add successive 200ul aliquots of NaOH. Allow the pH to stabilize after each aliquot and record the pH of the original solution before the titration.
NOTE: You will acquire approximately 200 separate data points (pH vs volume NaOH) for each titration. Space is provided in the page below but, you'll have to be neat. There is an option to "keep" the data for export to a USB stick.
Basic Technical Mathematics
ISBN: 9780137529896
12th Edition
Authors: Allyn J. Washington, Richard Evans